The chassis dynamometer used in the performance evaluation test of the vehicle is widely used for a fuel consumption measurement test, an exhaust gas characteristic test, an endurance test and so on, because the test that corresponds to a travel of the vehicle on an actual road can be carried out easily indoors with good repeatability. In the vehicle travelling test by this chassis dynamometer, in order for the driver to drive with the repeatability, a driving pattern (the travelling speed pattern) by which a drive operation by the driver is done for the performance evaluation of the vehicle is displayed on a monitor (a driver's aid display).
Driver's aid is the one that indicates or displays at what speed the driver should drive the tested vehicle. As an example of the travelling speed pattern indicated by the driver's aid, it is a driving pattern such as “10·15 mode” and “US06 mode” (see, for instance, Patent Documents 1 and 2). The performance evaluation test is carried out by the fact that the driver drives the tested vehicle on the chassis dynamometer so as to follow this travelling speed pattern.
When the driver drives the tested vehicle while following the travelling speed pattern, the driver of the tested vehicle is required to drive so that mainly a speed of the tested vehicle corresponds to the travelling speed pattern all the time. Therefore, in order that the driver of the tested vehicle can check other information (e.g. a throttle opening, a gradient of the road surface, and the like) while checking the travelling speed pattern information and the actual speed of the tested vehicle, information that is necessary for the performance evaluation test of the vehicle is displayed on the driver's aid display (see, for instance, Patent Documents 1˜5).
Currently, a performance evaluation manner of the vehicle diversifies, and not only the above exhaust gas test is required, but also it is required that a travelling test on the actual road that is not normalized should be replicated on the chassis dynamometer. In a case where the travelling test on the actual road is replicated, the vehicle actually travels on the road where the travelling test is carried out, thereby collecting road data (see, for instance, Patent Documents 6 and 7), then the travelling speed pattern is created on the basis of the collected data and is displayed on the driver's aid display. The collection of the road data is made a plurality of times, and by averaging them, the accuracy of the travelling speed pattern is improved.